A known form of a bedding product comprises a plurality of bands of springs disposed side-by-side and connected with helical lacing wires. Most often these continuous bands of springs extend longitudinally and the helical lacing wires extend transversely of the bands and embrace portions of the bands. Several different kinds of bands of springs have been proposed for incorporation into spring interiors of bedding mattresses. One kind of band which is the subject of British patent no. 2,143,731 will hereinafter be referred to as a band of interlocked or interlaced springs. In addition, U.S. Pat. Nos. 4,053,956 and 4,112,726 disclose a band of springs made of a single piece of wire without the convolutions of the coil springs being interlocked or interlaced. In either case, such a band comprises a single length of wire formed to form a plurality of individual coil springs arranged in a row, one end turn of each coil spring lying adjacent to a top face of the band and the other end turn of the coil spring lying adjacent to a bottom face of the band, each coil spring being of a rotational hand either opposite to or of the same rotational hand of the adjacent coils immediately before it in the row and being joined to the adjacent coil springs by a plurality of interconnecting segments of wire integral with the coil springs. One of the pair of interconnecting segments is located in the bottom face of the band and the other of the pair of interconnecting segments is located in the top face of the band.
Another well known type of spring interior of a mattress or cushion comprises a pocketed spring assembly. One type of pocketed spring assembly comprises a plurality of pockets joined together, each pocket containing a continuous row of coil springs. Fabric material is commonly sewn, welded, glued or otherwise secured around a band of continuous coil springs so as to enclose the band within a pocket of fabric. The pockets are then joined together to form a pocketed spring assembly.
U.S. Pat. No. 5,669,093 issued to the assignee of the present invention and herein incorporated by reference discloses a plurality of integrally connected fabric blocks or pockets, each containing a band of coil springs. The blocks or pockets are connected to each other with lines of attachment. Successive lines of attachment are located alternatively in the upper and lower planar surfaces of the assembly as disclosed in U.S. patent application Ser. No. 08/821,393 which is also incorporated by reference herein.
Another patent which discloses a pocketed spring assembly is U.S. Pat. No. 5,127,635 also issued to the assignee of the present invention. This patent discloses a pocketed coil spring assembly in which longitudinally extending bands of coil springs made of one continuous piece of wire are enclosed in fabric covers to form longitudinally extending strips. Within each strip, individual pockets encasing one or more coil springs of a band are formed by connecting opposite sides of the fabric together between the individual coil springs. The fabric pockets are adhesively secured together with conventional adhesive with or without foam pieces inserted between the longitudinally extending strips.
Another known type of spring assembly comprises a plurality of three-sided spring containing strips joined together in order to make a spring assembly. Each strip contains a plurality of individual coil springs placed within a three-sided strip or pocket of fabric, one side of the strip being open. The individual coil springs within the strip are separated from each other by individual fabric partition members which are sewn or otherwise secured to the top and bottom of the three-sided fabric strip. A plurality of strips are aligned and sewn together in order to make the desired size of spring assembly. U.S. Pat. Nos. 1,663,272 and 1,724,947 disclose such spring containing strips and spring assemblies. One disadvantage to this type of spring assembly is that a separate piece of fabric (partition member) must be sewn between each individual coil spring thus increasing the time and labor costs required to make a strip and an assembly of strips.
Therefore, it has been one objective of the present invention to provide a three-sided spring retainer capable of holding a band of coil springs made of a single length of wire.
It has been another objective of the present invention to provide a three-sided spring retainer in which the individual coil springs are held in place without the use of additional strips or partitions of fabric material.
It has further been an objective of the present invention to provide a spring assembly in which three-sided spring retainers or strips are encased within conventional fabric pockets and multiple pockets joined to make a spring assembly.
It has been a further objective of the present invention to provide a three-sided spring retainer which may be manufactured less expensively than heretofore known three-sided spring retainers.